The aim of the proposed research is to: (1) Study the enzymatic control of phosphorylation and dephosphorylation in H5. (2) Investigate the significance of major and minor sites of phosphorylation in H5. (3) Determine the structure and function in the C-terminal half of the H5 molecule. (4) Study the metabolism of H5 in the chick/HeLa heterokaryon.